// number: floating point number-> Used for decimal and integers//用于十进制和整数
// String: Sequence of characters(字符·序列)-> Used for text//用于文本
// Boolean: true or false//真或假
// Array: Ordered list of values//有序值列表
// Object: Unordered set of key-value pairs//无序键值对集合
// undefined value taken by variable that is not yet define ('empty value')
// null:Also means"empty value"
// BigInt: larger integer than the Number type can hold//任意精度整数



/*console.log(true)
let javascriptIsFun = true;
console.log(javascriptIsFun);

console.log(typeof ture);
let age = 30;
age = 31;

const birthYear = 1991;//can't be changed

var job = 'teacher';
lastName = 'Schmedtmann';*/

const ageJosnas = 2023 - 1991;
